The correct answer is C. Governor.
The Governor is the head of state of Karnataka. He/She is appointed by the President of India on the advice of the Central Government. The Governor has the power to dissolve the Legislative Assembly, appoint the Chief Minister and other Ministers, and to give assent to Bills passed by the Legislative Assembly.
The Chief Minister is the head of government of Karnataka. He/She is elected by the members of the Legislative Assembly. The Chief Minister has the power to appoint the other Ministers, to allocate portfolios to them, and to preside over the meetings of the Council of Ministers.
The Prime Minister is the head of government of India. He/She is elected by the members of the Lok Sabha, the lower house of the Parliament of India. The Prime Minister has the power to appoint the other Ministers, to allocate portfolios to them, and to preside over the meetings of the Cabinet.
The President is the head of state of India. He/She is elected by an electoral college consisting of the elected members of both houses of the Parliament of India and the elected members of the Legislative Assemblies of the States. The President has the power to appoint the Prime Minister, the Chief Justice of India, and other judges of the Supreme Court and the High Courts, to declare war, to conclude treaties, and to issue ordinances.